1. Field of the Invention
The present invention relates to a lens module for an imaging apparatus.
2. Description of Related Art
The focal length of a lens of an imaging apparatus varies depending on the ambient temperature because its refractive index changes with its temperature, causing the performance of the imaging apparatus to be lowered.
To deal with such a problem, PCT International Publication No. WO 2009/101928 describes a technique in which a lens is mounted on the surface of a lens-holding plate, the linear expansion coefficient of the lens being larger than that of the lens-holding plate so that the refractive index change due to the temperature change of the lens is compensated utilizing the difference in linear expansion coefficient between the lens-holding plate and the lens.
However, the technique has a problem that the lens-holding plate is required as an additional member to compensate the refractive index change of the lens, causing the parts count of the imaging apparatus to increase.